Phpunit testing with database

If you want to test your business logic: Mock away the Database class and return fake data

If you want to test the class that fires the SQL statements (and imho you could test that too since I kinda wanna know if my code works fine with a real db in the backend) it gets a little complicated but there are ways to do it:

• Using setUp() and tearDown() to get a consistent state for your data before running your tests is (imho) a fine way to write db-driven unittests. It can get annoying to write lots of custom sql by hand though.

• To make your life a little easier you can look into the DbUnit extension and see if that works for your Application.

• If you really want to dive into Unittesting database interactions the best read on the subject is (imho) the chapter on db-unittesting in Sebastian Bergmanns phpqa book.

• Could your application allow for a custom database name and automated setup of all tables it may also be possible to set the db up once with a lot of testdata and use that data in all your tests. You could be carefull so though that one test doesn't rely on data written by another one.

Run tests with other copy of the database that is empty and/or cleared in setUp() or tearDown() methods, but be careful not to do what github did.

If you're using a good database (i.e. not MySQL with MyISAM tables) you can wrap test in a transaction and roll it back after the test:

 function setUp() { $this->db->exec("BEGIN"); }
 function tearDown() { $this->db->exec("ROLLBACK"); }

The downside is that you can't test code that uses transactions (unless you abstract that and emulate with savepoints, but that's iffy).

Ideally you should use dependency injection and run tests on fake database class:

$fakedb = new DatabaseThatDoesntReallySaveThings();
$user = new Model_User($fakedb, $userData);
$user->save();
$this->assertTrue($fakedb->wasAskedToSaveUser());